Characterization of SrAl_2O_4:Eu~(2+), Dy~(3+) phosphor nano-powders produced by microwave synthesis route

摘要

SrAl_2O_4 phosphor nano-powders activated with heavy elements such as Eu and Dy were prepared by microwave synthesis method. Using this method led to the reduction of processing time. Various calcinations times have been employed to produce pure SrAl_2O_4:Eu~(2+), Dy~(3+) phosphor materials. It was found out that microwave synthesis technique led to reduction of optimum calcinations time to 9 min. XRD analysis showed that the powders were nearly pure SrAl_2O_4 phase, in which the SrAl_2O_4 host phase has the maximum fraction of monoclinic SrAl_2O_4 phase. The critical pH to achieve pure SrAl_2O_4 phase determined to be equal to 4. For the synthesized SrAl_2O_4:Eu~(2+), Dy~(3+), the properties of photoluminescence such as emission, excitation and decay time were examined. Fluorescent spectrophotometer results revealed that two excitation peaks are appeared at 280 and 339 nm and an emission peak at 515 nm. The crystallite size of these pigments is about 58.22 nm after calcinations for 9 min in microwave as determined by Scherrer' s formula. SEM was used to study the morphology and shape of powders.